13 times the U.S. almost destroyed itself with its own nuclear weapons

In two days, it will be the 69th anniversary of the the first ever atomic test, conducted in the deserts of New Mexico on July 16, 1945. The bomb was found to have the same destructive force as 15,000 to 20,000 tons of TNT, according to PBS. PBS also gave an account of General Leslie Groves, who was there to witness the testing and described it as "successful beyond the most optimistic expectations of anyone."

However, the U.S.' record with nuclear weapons has not always been quite as "successful" as its first atomic test. In fact, the U.S. has had several close encounters with its own nuclear weapons that could easily have ended in disaster. Compiled here are the stories of 13 nuclear near-misses of catastrophic proportions.

January, 1961: Goldsboro, North Carolina

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"By the slightest margin of chance, literally the failure of two wires to cross, a nuclear explosion was averted," said Secretary of Defense Robert McNamara of the two nuclear bombs accidentally dropped on Goldsboro, North Carolina.

McNamara was speaking, according to CNN, about the damaged mechanism that was the sole preventer of a nuclear explosion in Goldsboro.

The two bombs were released when the Air Force bomber that was carrying the weapons broke in half midflight. The parachute for the first bomb, pictured left, activated and prevented detonation. The parachute for the second bomb failed to open, and the bomb was armed when it hit the ground.

Had it exploded, CNN calculates that it would have killed 28,000 people and injured 26,000, emitting radiation over a 15 mile radius.

Five of the eight man crew survived the bomber crash.

October 25, 1962: Duluth, Minnesota

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A midnight intruder at the Duluth Sector Direction Center almost led to a nuclear strike, according to the Nuclear Files website.

A guard at the compound shot at the intruder, who was in the act of climbing the fence. This shot activated the "sabotage alarm," which triggered warnings at all military bases in the area including the base at Volk Field, Wisconsin.

The Volk alarm had been wired incorrectly, and instead of a simple warning the system ordered nuclear armed F-106A interceptors to go to the alarm's point of origin — Duluth. Due to the Cuban Missile Crisis, the country was at DEFCON 3, a time when there were no practice drills. The pilots expected to be dropping their nuclear payload that night.

Immediate communication came from Duluth, informing Volk that something had been miscommunicated and a nuclear strike was not needed. The planes, which were already headed down the runway towards Minnesota, were called off by a car that raced from the Volk command center as soon as the communication from Duluth was received, stopping the planes' takeoff.

The intruder was later revealed to be a black bear.

September 19, 1980: Damascus, Arkansas

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An Air Force repairman conducting maintenance on a Titan II ICBM missile silo in 1980 almost caused a nuclear explosion, according to History.com website.

The repairman accidentally dropped a wrench into the silo, and the heavy tool punctured the fuel tank of the missile. The missile leaked fuel for over eight hours before it finally exploded, killing a service member, injuring 21 others, and destroying the compound where the silo was held.

Despite the massive blast, the nuclear warhead was recovered intact.

November 9th, 1979: Washington, D.C.

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On the morning of Nov. 9, four American command centers including the Pentagon and the Strategic Air Command’s bunker received a message that Russia had launched a massive nuclear strike, according to Listverse.

The U.S. prepared retaliation missiles and conducted an immediate threat assessment conference. After six minutes of scanning airspace and satellite data, no Russian missiles were found, and the U.S. found no need to return fire.

The cause of the alarm was later found to be a military training tape describing a fictional Soviet attack. The tape had accidentally been loaded into the early warning computers. After the scare, a new facility was created for the sole purpose of running these training tapes in isolation from other compounds.

March 14, 1961: Yuba City, California

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When the pressurization system of a B-42 carrying two nuclear weapons began to fail at 10,000 feet, the Air Force commander on board ordered his crew to abandon ship, according to History.com.

The commander, meanwhile, stayed on board the failing aircraft in order to steer the plane away from the densely populated areas of Yuba City, California, that the plane was directly over.

The commander bailed from the plane at 4,000 feet after steering the plane away from populated areas. The plane crashed several miles from the city and the weapons were torn from the plane, although their safety mechanisms prevented them from exploding or releasing any contamination.

May 22, 1957: Kirtland Air Force Base, New Mexico

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A nuclear bomb was being transported from Texas to New Mexico when it fell 1,700 feet from the bomb bay doors into a field near the city of Albuquerque. Nobody knows exactly why the bomb fell, but its traditional explosives detonated, leaving a crater 12 feet deep and 25 feet wide, according to History.com.

The city of Albuquerque was saved by a safety protocol; the nuclear explosives had been separated from the rest of the bomb for safety during transport. The nuclear capsule was later found intact, and the only casualty of the event was a cow grazing too close to the detonation site.

February 5, 1958: Savannah River, Georgia

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During a training simulation, a B-47 that was carrying a nuclear weapon had a midair crash with an F-86. Fearing the worst, officials ordered the nuclear weapon aboard to be ejected from the plane and into the river below, according to History.com.

The conventional explosives in the bomb failed to detonate and the nuclear capsule, which had not been installed in the weapon during the training exercise, remained intact.

Despite extensive searching, the Air Force never found the bomb in the river.

November 4, 1958: Dyess Air Force Base, Texas

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A plane carrying a nuclear warhead burst into flames during takeoff at the Dyess Air Force Base in Texas, leading to an explosion and the death of a crewman aboard the plane, according to Reporter News.

The traditional explosives went off, although the nuclear core remained intact and was recovered later at the scene.

Butterfield Elementary School was only about half a mile away from the explosion. No one at the school was harmed.

March 11, 1958: Florence, South Carolina

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A suburban neighborhood in Florence, South Carolina was rocked by an explosion in 1958 as a thermonuclear weapon fell from a B-47E aircraft overhead, according to the Daily Mail.

The three-ton bomb was accidentally jettisoned from the aircraft soon after the plane took off when the pilot, looking for the bomb's locking pin, grabbed the emergency bomb release instead. The nuclear core of the bomb was stored elsewhere in the plane, preventing a nuclear accident.

The bomb destroyed a playhouse in the woods behind the Greggs family's house. The Greggs' two little girls Helen and Frances, along with their cousin Ella Davies, had been playing in the playhouse just minutes before the bomb fell. If they had remained in the house any longer, they would have been the first Americans killed by a nuclear weapon on U.S. soil.

October 11, 1957: Homestead Air Force Base, Florida

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Soon after liftoff from the Homestead Air Force Base, the tire of a B-57 carrying a nuclear device exploded. The explosion crashed the plane into a field, where the aircraft burned for four hours, according to the U.S. National Security Archives website.

The traditional explosives in the bomb caused two explosions as the plane burned. The nuclear capsule and its carrying case, however, were found intact and only slightly damaged by the fire.

The fire damaged the nuclear capsule and its protective case, causing nuclear leakage and contamination. However, this contamination was limited to the immediate area of the destroyed aircraft.

October 15, 1959: Hardinsberg, Kentucky

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A B-52 carrying two nuclear weapons and a KC-135 meant to refuel the B-52 midair collided over Kentucky, according to the U.S. National Security Archives website. The collision caused both planes and both bombs to fall to earth.

The crash killed four crew members of both the B-52 and the KC-135. The two nuclear weapons were discovered in the crash, unarmed and only slightly damaged — not enough to cause radiation leakage.

The plane, about to take off from Bunker Hill (now Grissom) Air Force Base struck an electrical manhole box and caught fire. One crewman was killed, and portions of all five weapons burned. The contamination released by the damaged nuclear weapons was contained in the immediate area of the crash and immediately disposed of.